sistawendy: my 2006 Prius at the dealership (Prius)
sistawendy ([personal profile] sistawendy) wrote2009-05-07 09:23 pm
Entry tags:

the state of the bike

Not so good: After nine months of commuting up and down suburban hills, I need to replace my brake pads. I've also worn out the ratchet on the grip shifter for my rear derailleur. REI dude says shifters come in pairs. Goldiebike was in mint condition when I bought her, so I'm a little leery of replacing anything big so soon.

Not so bad: At least the friction in the shifter keeps it from surprising me while I ride.

Good: After several months of one puncture per month, I bought a pre-slimed tube in January. It's still good. It was twice the price, but I've already gotten three times the use out of it.

Weekend nun plan? I'm thinking Chillography over at the Church of Bass.

[identity profile] randomdreams.livejournal.com 2009-05-08 04:52 am (UTC)(link)
Grip-shift brand of shifters?
Don't have to be replaced in pairs.
Check recycled cycles. They're likely to have a replacement right-hand one. Or they might even have suggestions about just swapping out the detent mechanism, because in a GS it's just a spring, a ball bearing, and a carefully shaped series of dents in a bit of material, and what you're facing is either a broken spring or more likely a worn out series of dents, and those are typically both replaceable.
[livejournal.com profile] ziptie might have some suggestions about this, as well; he has done some GS work and found parts in Seattle.

[identity profile] sistawendy.livejournal.com 2009-05-08 05:16 am (UTC)(link)
Grip-shift isn't the brand. As I recall, the brand is Sram.

[identity profile] randomdreams.livejournal.com 2009-05-08 05:25 am (UTC)(link)
If I remember correctly, SRAM bought Grip-Shift in the late '90's, and still use the same mechanicals. I haven't worked on anything newer than about 2001, but at that point they were still the same internals as they'd been since their original introduction.
I cannot think of any reason they'd need to be replaced in pairs.
It is possible you'd have to replace both the right shifter and the rear derailleur, since they're calibrated as a pair and SRAM might have changed the winding ratio, but even then, you could find an old rear shifter and it should work fine with your existing derailleur.

[identity profile] sistawendy.livejournal.com 2009-05-08 05:32 am (UTC)(link)
I think REI Dude's point was that he'd have to order them in pairs, unless they happened to have one lying around. He also told me that the right a.k.a. rear shifter is the one that most often needs replacement, which I find surprising as sunrise.

I didn't see an obvious way into the shifter to replace the detent mechanism, but I am only an egg at this bike repair.

[identity profile] randomdreams.livejournal.com 2009-05-09 12:16 am (UTC)(link)
GS's are held together radially with allen bolts, basically, and a lot of the innards are apparent when you get them off the handlebar. The shifter ring is constrained onto the part that encircles the handlebar, which holds in place by a hose-clamp-like mechanism. So when you slide off the grip (which you do by lifting a corner by pinching it up and sticking a little screwdriver in there, then pouring in a couple ml of isopropyl alcohol and then scootching the grip back and forth so the alcohol spreads, which will get the whole grip off in a few moments) then you slide off a washer that butts against the grip, loosen the clamp mechanism and slide off the shifter ring, and the whole works comes apart in your hands. As I recall, there are only two moving parts and one bending-moment part in a GS.

And yeah, I'm sure he's right about them showing up new in pairs. I hadn't thought about that since I tend to buy used.